A Bis‐Boron Amino Acid for Positron Emission Tomography and Boron Neutron Capture Therapy
Junyi Chen, Mengxin Xu, Zhu Li, Ziren Kong, Jie Cai, Chunhong Wang, Bo‐Shuai Mu, Xi‐Yang Cui, Zizhu Zhang, Tong Liu, Zhibo Liu
Abstract
Abstract Trifluoroborate boronophenylalanine (BBPA) is a boron amino acid analog of 4‐boronophenylalanine (BPA) but with a trifluoroborate group (−BF 3 − ) instead of a carboxyl group (−COOH). Clinical studies have shown that 18 F−labeled BBPA ([ 18 F]BBPA) can produce high‐contrast tumor images in positron emission tomography (PET). Beyond PET imaging, BBPA is a theranostic agent for boron neutron capture therapy (BNCT). Because BBPA possesses an identical chemical structure to BNCT and PET, it can potentially predict the boron concentration for BNCT using [ 18 F]BBPA‐PET. The synthesis of BBPA was achieved by selectively fluorinating the α‐aminoborate compound, taking advantage of the varying rates of solvolysis of the B−F bond. The study showcased the high‐contrast [ 18 F]BBPA‐PET imaging in various tumor models, highlighting its broad applicability for both [ 18 F]BBPA‐PET and BBPA‐BNCT. [ 18 F]BBPA‐PET tumor uptake remains consistent across various doses, including those used in BNCT. This enables accurate estimation of the boron concentration in tumors using [ 18 F]BBPA‐PET. With its dual boron structure, BBPA increases boron concentration in tumor cells and tumor tissues compared to BPA. Thus, less boron carrier is needed. This study introduces a new theranostic boron carrier that enhances boron accumulation in tumors, predicts boron concentration, and enhances the accuracy and effectiveness of BNCT.